The invention concerns an instrument for simultaneously measuring a succession of cylinder bores, especially the bores in the bearing lanes of motor blocks, cylinder heads, and similar structures, with respect to shape and alignment.
An instrument of this type and for this purpose is known from the sales literature PAT MULTI-INCOMETER. The instrument is a mobile piece of equipment used to measure a succession of bores like the bores in a crankshaft bearing lane for roundness, geometrical defects, and alignment. It has a probe that operates in conjunction with two motors and a drive mechanism, generating a rotary motion and an axial motion, that is provided with heads associated with the bores in the work that are to be measured with respect to number and position, and that extends when employed as intended through the bores. The probe rotates and slides back and forth in bearings at each end. The bearings can be secured to the particular face of the work by a universal suspension, allowing angular error in the faces of the work to be compensated for within design-dictated limits. The drive unit that the end of the probe extends through is flanged to one of these bearings.
The known instrument has been proven outstanding for measuring bearing lanes that have large-measure bores and/or are not too long. For very long bore lanes and/or small-diameter bores on the other hand there is an unacceptable risk of contaminated results because the drive unit flanged like a projecting collar onto one of the probe's bearings exerts bending moments on the probe that can distort it in ways difficult to correct for.